Permanent installation batching plants are expensive to construct and operate. The usual practice is to drive a self-transit mixer truck to the batching plant, where it is charged with the ingredients for making the concrete. The transit mixer truck then delivers the product to the building site while the drum, which receives the charge, slowly rotates.
A problem arises when the construction site is a far distance from the batching plant, because the self-transit mixer takes an inordinate time to receive the concrete mixture and deliver it to the pour point. It is not economical to use a self-transit mixer truck over long hauls.
Transportable batching plants have been proposed to cover these special situations where the hauling distance is too great, by locating a transportable temporary batching plant closer to the construction site. An example of this is shown in U.S. Pat. No. 2,756,881, "BATCH LOADER FOR DRY-MIX CONCRETE", issued to R. W. Sims, July 31, 1956.
The successful use of a portable batch plant depends upon the ease with which it can be moved overland, to a point where there exists the raw material for making the dry mix and which is also as close as possible to the construction site. While the concept of the transportable batch plant is good and has a worth which has been demonstrated over many years' use, there is, nevertheless, drawbacks to an arrangement of this type, because the transportable batch plant tends to be a cumbersome device to transport, and sometimes lacks stability and safety when raising the bin or container from a lowered position where it receives the charge to a raised position wherein it dispenses the load into the charge opening of a transit mixer.
The function of a transportable batch plant is to receive and weigh the dry ingredients of concrete mix and then dispense them from a vertically raised position into a self-transit concrete mixer truck. By reducing the distance between the batching point and the building site, a self-transit mixer can be employed more efficiently.